1. Field of the Invention
This invention relates to a method of and an apparatus for manufacturing slide fastener stringers having a discrete formation of selectively colored coupling elements
2. Prior Art
There are known a variety of slide fasteners having rows of discrete coupling elements made of a metallic material such as gold, silver, copper and the like which presents its intrinsic monochromatic hue. However, to the best knowledge of the present inventors, there has been proposed no such slide fastener which carries metallic or resinous coupling elements of different colors arranged in an alternate distribution along a longitudinal edge of the stringer tape. Attempts have been made to produce slide fastener stringers having coupling elements of such various colors which would be attractively compatible with garment articles of versatile designs and styles to which the slide fastener is applied. One such attempt was to supply a mix of differently colored coupling elements from a parts feeder or hopper to an element applying station where the elements are applied to fastener stringer tapes, in which instance a photoelectric sensor was used to sort out a group of elements of the same color. This operation was not only time-consuming but also often hindered by the presence of irregularities in the hue of each individual element and the influence of ambient light.